Flying versus walking. A no-contest, you might think, but many bird species have abandoned the wind beneath their wings for the earth beneath their feet, and nowhere are these pedestrians better represented than in New Zealand. What is the attraction of a life on the ground that sets the kiwi, and dozens of other birds, to striding rather:than soaring?

Magazine

Jan - Mar 1998

On November 9, 1997, three Department of Conservation biologists, Jeremy Carroll, Dave Barker and James Fraser, with trained bird dogs Bob, Gus and Fiddich, landed on 19 ha Jacquemart Island, just south of Campbell Island. In typical subantarctic fashion, it was raining heavily, with regular bursts of snow, and the wind was 30 knots.
The group had a mere three hours to spend ashore on an island which had been visited by scientists only twice previously—in 1980 and 1984. They were hopeful of discovering an additional population of the Campbell Island teal, a duck species long thought to be extinct, but rediscovered on nearby Dent Island in 1975. Dent Island is of similar size to Jacquemart, and home to no more than 50 of the flightless ducks.
Within ten minutes of landing, one of the dogs had flushed a bird. To the biologists' surprise, it wasn't a duck, and it could fly, albeit weakly. Fifty metres away, the dog found a second specimen, which was captured and photographed before being released. It proved to be a snipe—a bird unknown from the Campbell Island area.
Subfossil bones indicate that the New Zealand snipe Coenocotypha aucklandica once roamed the country, but probably disappeared from the mainland after Polynesian rats were brought here. A single specimen was taken on Little Barrier Island in 1870, but this is the nearest record to a mainland occurrence in recent times. The bird seems unable to survive in the presence of any mammals, with the exception of the house mouse. Weka also prey upon its eggs and young.
Three named subspecies of New Zealand snipe survive, each on its own island: Coenocotypha allele­landica huegeli on The Snares, C. a. meinertzhagenae on the Antipodes and C. a. aucklandica on the Auckland Islands. There is a separate species on the Chathams. No snipe have ever been found on Campbell Island, al­though they once lived on Stewart Island (exterminated by rats from Big South Cape Island in 1964). The nearest population of New Zealand snipe to Campbell Island is on the Auckland Islands, 340 km distant.
The new bird is similar to the other subantarctic snipe but has a longer bill and more dorsal markings, which may mean that it is a new species or subspecies. DNA analysis of blood samples from all the varieties needs to be done to establish the true taxonomic status of these birds.
Snipe are wading birds in the same family as godwits, curlews and sandpipers. The New Zealand snipe, how­ever, is not a bird of estuary or river; it prefers tussock, scrub and forest, and only ventures into the open at night. The Field Guide to the Birds of New Zealand reports that ghostly nocturnal whistles made by the Stewart Island snipe were apparently the source of the hakawai of Maori legend: a frightening creature of the night.
During the course of the few hours ashore on Jacquemart, three birds were seen, and the dogs' behav­iour indicated the presence of up to 10 birds in the part of the island which was traversed. Given the amount of suitable habitat, there may be up to 60 individuals living on the island.
To formally name a new species or subspecies, a type specimen (preferably a whole animal, though sometimes just a single bone) is usually required to be lodged in a mu­seum. Early ornithologists such as Walter Buller had no qualms about killing and mounting a specimen, even, if it was the last individual of a species.
Buller saw it as "species conservation." Times have changed. Sacrificing a specimen of a rare species is now about as socially acceptable as terrorism. In the case of the new snipe, it is conceivable that a bone from a long-dead individual could be recovered from Campbell Island (since landing on Jacquemart is so difficult). Snipe probably once lived on Campbell, before rats and cats arrived. No cats have been sighted for several years, but rats are certainly present. The discovery of this snipe will increase pressure for the eradication of rats from Campbell Island, in the hope that the bird can be re­established there.

Most visitors to northern New Zealand never pass through border controls. They arrive without visas, delivered by ocean currents from the subtropics, and include marine reptiles, planktonic drifters, molluscs and fish. Some settle here, bringing tropical colour to the reefs of New Zealand's north-east coastal headlands and islands.
The currents that bring such creatures here lie on the western boundary of a wind-driven gyre, a slowly rotating anticyclonic whirlpool which circulates surface waters around tile southern Pacific Ocean. Water from the Coral Sea and Great Barrier Reef flows southwards as the East Australian Current. At about the latitude of Sydney the water crosses the Tasman Sea, passing Lord Howe Island and Norfolk Island as the broad meandering Tasman Current. The flow continues around Cape Reinga as the East Auckland Current and runs along the continental shelf edge off the North Island's north-east coast.
Among the many creatures these currents deliver to our waters are five species of sea turtle. Turtle sightings go back over 200 years: Joseph Banks and Captain Cook saw a sea turtle from Endeavour near Ninety Mile Beach. The world's largest turtle, the leatherback, which can grow to 2.8 m in length, is the one seen most often. Leatherbacks regularly venture into colder waters and have been reported from the South Island. Others, such as the green and loggerhead, are accidental visitors, and sightings are largely confined to Northland.
Venomous sea snakes also find their way here, but our seas (particularly during winter) are really too cold for them. The most frequent such visitor is the yellow-bellied sea snake, an animal that truly "goes with the flow," spending its entire life at sea travelling with currents. It is the world's most widely dispersed reptile, and can be found from the east coast of Africa to the west coast of the Americas. Drifting has its drawbacks, for the snake will die if it is delivered to a cold latitude too far north or south, or if it becomes beached or trapped in a rock pool. Other sea snakes that make rare appearances in New Zealand are the black-and-white banded varieties that can come up onto land. One was found alive on a Te Aroha riverbank in 1945,20 km from the nearest estuary.
Most marine animals travel to New Zealand's north-east as tiny planktonic larvae, an intermediate stage between egg and adult. Likely sources for larvae are the islands upstream from New Zealand-Lord Howe Island and Norfolk Island.
The East Auckland Current also delivers packets of warm water, creating an environment in which these creatures can settle and grow. Malcolm Francis, a NIWA marine biologist who has studied the distribution of New Zealand fish species, has shown that the north-eastern North Island has about 170 recorded inshore fish species, the highest number for any New Zealand coastal region. Approximately 10 per cent of them are tropical strays that make cameo appearances only during warm periods. Around a third are subtropical in origin, their population centres lying astride the Tropic of Capricorn. Some of them are breeding locally, but their populations are also being restocked by individuals arriving as larvae.
Moray eels are an example of a tropical and subtropical group. They spend two to three weeks in the plankton as eggs and then change into larvae several centimetres in length, remaining thus for two to three months. The seven species of moray are also native to such places as Australia, Lord Howie Island and Norfolk Island.
An example of a tropical stray is the lionfish, a gaudy species with large poison-tipped pectoral and dorsal fins, seen in 1990 off Ngaio Rock at the Poor Knights Islands. It was a small specimen, probably delivered with the current as a planktonic larval fish.
Hard evidence of the life carried to New Zealand by ocean currents can be found on the beach. New Zealand records for tropical molluscs-marine snails, bivalves, nautiloids-are based in many cases on a few recovered shells. Fewer than 100 of our 2000 species of marine molluscs are of tropical or subtropical origin.
Margaret Morley, a shell collector and researcher, once found a rare orange-and-white subtropical cone shell (Conus lischkeanus kermadecensis) alive in Parengarenga Harbour. This 6 cm snail remains submerged during the day in the soft intertidal mud, coming out at night to feed, which it does by stabbing marine worms with a single poisoned harpoon-shaped tooth. Specimens of this species have been recovered as far south as White Island. Bruce Marshall of the Museum of New Zealand has suggested that this warm-water cone snail may have established a breeding colony off Spirits Bay, Northland. The rare specimens found along the coastline could originate from larvae produced by this colony or from parents outside New Zealand.
Cowries have been found alive off our north-east coast in the last few decades. But some shells found cast up on northern beaches come from creatures that probably do not live here. In this category would be cuttle bones and the shells of chambered nautilus, both from the octopus and squid group of molluscs. These structures hold air-the nautilus shell in its scaled chambers, the cuttle bone in the interstices of its matrix-so can float for great distances, borne by wind and currents.
Some warm water species arrive (perhaps on ships rather than as larvae) and become significant components of our fauna, the much cultivated Pacific oyster being a prime example. Others seem to thrive here for a few years, then fade away. One such is a small bivalve, the white file shell Limaria orientalis which became very abundant around northen New Zealand for a few years two decades ago. It otherwise occurs in parts of Australia, the Philippines and Japan.
The best way to meet these marine immigrants is to go for a dive or snorkel around some of northern New Zealand's coastal islands and headlands. At the Poor Knights Islands, where the water is one to two degrees warmer than on the coast, many warm-water organisms thrive. They include crimson red toadstool groupers, Lord Howe coral fish, banded coral shrimps, moray eels, long spined sea urchins, cone snails and colourful subtropical sea slugs. Other islands in this warm stream include the Mokohinau Islands, the northern tip of Great Barrier, Mercury, Mayor and White islands. Coastal headlands such as Cape Brett project out far enough to also receive some of this stream of immigrants.
Sometimes the larvae-bearing water of the East Auckland Current runs inshore. During the spring and summer months of the late 1980s there were many tropical fish sightings between Cape Reinga and Leigh. These were La Nina years which brought warmer than usual weather to northern New Zealand with more north-east winds. Researchers Malcolm Francis and Jo Evans have reasoned that these winds diverted the East Auckland Current inshore by a frictional effect at the sea surface.
What effect is the present El Nino having on New Zealand's northeast? During the spring and early summer months of 1997, cool west to south-west winds prevailed. These winds blew warm surface water offshore and this was replaced by relatively cold water upwelling from the deep. This water was rich in nutrients and when it was exposed to sunshine it became murky-the result of algal blooms. It is unlikely that immigrant warm-water species could comfortably settle under these circumstances.
At the time of publication, the winds are following a different pattern which is more like a La Nina than an EI Nino. Tropical northerly winds are prevailing, and the coastal water is warmer than usual. These conditions are more favourable for the settlement and surival of immigrants from the north. We can only wait and see whether this will result in a new influx.

Ex ovo omnia- "everything is from an egg"-is a concept unlikely to trouble readers of this journal, unless they were to consider what might hatch from an egg long enough to yield 30 identical slices when hard boiled-and what might have laid such an egg.
Visitors to the 21st ECNZ National Science and Technology Fair, held in December at the Museum of Transport and Technology in Auckland, will have it cracked. Anna Pilbrow, a 7th-former at Christchurch's Burnside High School, won the premier technology award for constructing such an egg. Anna saw a need in the catering industry for a "continuous, ready-to-serve" hard-boiled egg, one that would yield more than a paltry four slices. This she created by "rearranging" the contents of many hens' eggs into a long cylinder and hard-boiling the mixture. The resulting tubular mega-egg, apart from its length, shares the characteristics of an ordinary hard-boiled egg, with the added advantage that garnish and colouring may be added before boiling.
Food was on the minds of a number of other entrants in the technology category. At Taupo Intermediate, Simon Smith developed a more refined version of the can-on-a-stick fruit picker. Simon's came complete with adjustable pole, collector bag and stalk-cutter.
The bag, fitted beneath a neck made from a bottomless tin can, had a baffle system to minimise bruising, while a draw cord and toggle allowed easy release of fruit from the bottom. The cutter, a V-shaped piece of aluminium sharpened along its inner edges, doubled as a guide.
The bracket holding the tin can was adjustable, allowing the operator to get at fruit from different angles.
Frozen rather than fresh produce was the focus of Orewa College's Lisa Brooks. She noticed that food packaging in her local supermarket freezer was often wet, and that the freezer didn't feel very cold. Was poor storage resulting in food of reduced quality and an increased risk of bacterial infection?
Lisa thought an indicator on frozen food packets to show whether they had been stored at the correct temperature would be of interest to shoppers. Such a device would have to alter irreversibly on thawing just once, so customers could see at a glance if defrosting had occurred at any time.
After studying the difference between the frozen and unfrozen states, and what changes take place during thawing, Lisa came up with three successful indicators.
The first used a small slice of apple, which remained white while frozen but gradually turned brown on thawing: the longer the packet had been defrosted, the browner the apple. The second consisted of a white cotton pad with a non-absorbent X-shaped coating on one surface, placed over a small slab of red-coloured ice (a substance made to a "secret recipe"). If the ice melted, the pad, except for the X, absorbed the red solution. A white X on a red pad, therefore, indicated defrosting. The third was a tick-shaped piece of ice that became a shapeless blob when it melted.
Niklas Moore of Matarau School was more concerned about risks to New Zealand's radiata pine plantations than to human health. Would the use of other species to reduce our dependence on a single type of tree be advisable? He had seen bamboo being used for scaffolding in Hong Kong, and pondered its possible uses in this country.
Niklas produced a number of different textured bamboo fibres, from which, by mixing them with polyester resin and pressing in a homemade press, he made samples of fibreboard. Tests showed these to be equal or superior in strength to commercially available boards, indicating locally grown bamboo could be a viable alternative in the production of commercial fibreboard for the construction industry.
The exhibits of other budding technologists also proved Kiwi ingenuity to be alive and well: a comparative survey of the efficiency and humaneness of various mousetraps available on the market; a home-produced X-Zylo that outflies the commercial model; recyclable plant pots; a mask to be worn while travelling on aeroplanes to combat dehydration; a comparison of the noise levels produced by various items of domestic machinery.
In the science category, the premier award went to 4th-former Rawiri Waru of Rotorua Boys' High. Rawiri was interested in the effect of weather on the performance of geysers at Whakarewarewa. To supplement his field observations and background reading, he built two ingenious pieces of apparatus for laboratory tests. The first was a glass geyser, which allowed him to model fluid dynamics. The second was a geothermal simulator, complete with fault lines, hot aquifer, recharge systems, heat chamber, surface reservoir and geyser vents. By blocking off vents, streams and aquifer in various combinations, Rawiri was able to manipulate the circulation system and vary geyser activity accordingly. In particular, he recreated the effect of El Nino weather patterns-dry periods followed by short spells of heavy rain. His combined field and lab data allowed him to propose a model for the operation of Rotorua's famous Pohutu Geyser.
Not the boiling waters and sulphurous steam of New Zealand's geothermal areas for Virginia Dawson and Jacinda Ardern of Morrinsville College. They frequented the genteel domain of bowling greens in an attempt to identify and defeat a fungus causing damage to the billiard-cloth lawns. With painstaking effort, the 6th-formers isolated the fungus and ran trials to test a commercially available fungicide. The product proved to be not only expensive but also ineffective, and the pair embarked on the search for a soil bacterium that would do the trick. Samples of forest soil yielded a bacterium that inhibited the growth of the fungus, but not enough. Testing and trialling continues.
Also concerned with biological control was Amanda White of Nelson College for Girls. She developed a spray to keep down the numbers of psyllids-lea f-hopping insects-on the sweet-smelling boronia plant, cultivated for oil extraction. After testing the effect of psyllids on plants and researching both traditional. Maori and conventional methods of bug control, Amanda concocted a spray made from ngaio leaves, soap and water, which proved efficacious.
Pests of another kind were the focus of Haydn Luckman's project at Auckland Normal Intermediate. "Foreign invaders" such as possums, rats and mustelids cause extensive damage to native fauna and flora, and Haydn sought a means of control. His bait trials suggested a single bait could be developed to attract both herbivores and carnivores, targeting many species in one hit. Amongst the enticing ingredients were cheese, sausage, bacon and egg pie and mutton fat. Such morsels might run the risk of catching humans too!
Sailor David Tucker, at Napier Intermediate, was more concerned about controlling the speed of his boat, preferably making it go as fast as possible. Tests on the water to determine whether it travelled more swiftly on a lean or when level indicated heeling to leeward was fastest. However, subsequent mathematical testing using a technique called linear regression proved a level boat was faster under most conditions.
And if David ever wondered why his red socks looked maroon after a dunking, he could do worse than ask Christina McCombie and Meredith Rose at Otago Girls' High. They were intrigued that some things look darker when wet. Using a light-tight box of their own construction, with built-in goniometer (an instrument for measuring angles), they plotted the wet and dry reflectivity of various papers, cardboards, cloths, ceramics and painted surfaces. They used their measurements to gauge the predictive powers of the various theories on offer, all of which they found wanting in some degree.
Other young boffins rose to the challenge, shedding light on the possible medicinal properties of New Zealand native plants, the effectiveness of different acne-prevention products, the extent of lead pollution in Timaru, the sensory faculties of seagulls, the effect of differing CO, levels on the rate of plant growth and the ecology of the kotukutuku or tree fuchsia.
New Zealand's young scientists and technologists continue to do their country proud. Most of the winners of the 1997 national fair will be exhibiting in 1998 at the First Youth Science Festival of Asia Pacific Economic Co-operation in Seoul, and also receive an education scholarship.
Year by year, students have earned such rewards through mounting exhibits of increasing sophistication-identifying a problem or need, carrying out intensive research, running rigorous tests, learning from their mistakes and coming up with a new piece of knowledge or application.
Some have gone so far as to consider where their discoveries might actually be employed, or how their creation could be marketed, packaged, priced and patented. After all, if an egg can be tubular, why not also golden?

The First Nights with a new telescope are exhilarat­ing, as one pokes around the obvious targets: the Moon and the bright planets, the named stars and, with luck, the odd open or globular cluster.
But without further information the game can soon pall. The Moon is a lovely object, and one can browse the edge of the Earth's shadow night after night as it moves across the disc, throwing the craters and valleys into exaggerated relief. But how much are you really seeing? Unless you know where to look and what to look for, features at the limit of your telescope/eye performance are likely to escape detection. This holds for planetary detail as well. The chances are that the tyro will miss Cassini's division in Saturn's ring system or the fainter cloud belts of Jupiter unless guided by knowledge of their existence.
For the astronomer, as for the solo blue-water sailor, to ensure one's safe and timely arrival at the destination of choice a chart is a prerequi­site. While many targets are easily recognised once found, others cannot be positively identified without careful scrutiny.
But what chart? There is a wide range of printed material to choose from, beginning with simple guides to the naked-eye sky showing only the brightest stars and working on up to the two volumes of Uranometria 2000.0-473 pages of star plots down to magnitude 9.5. In between, there are a number of atlases, such as Wil Tirion's Bright Star Atlas and his Cambridge Star Atlas, which plot the 9096 stars to magnitude 6.5—the naked-eye viewing limit for an acute observer under a dark sky. These are excellent for sky gazing and binocular sweeping, but rather too sparse for telescopic work, since the faintest stars shown are too scattered for unskilled navigation amongst the myriad stars revealed by the telescope.
My personal favourite for work away from the convenience and shelter of an observatory is Tirion's Sky Atlas 2000.0, which plots 43,000 stars of magnitude 8 and brighter. It comes in a variety of formats ranging from the bound, coloured Deluxe Edition, very prone to dew damage, to the rugged, laminated Desk Edition, printed black on white. The Field Edition, white on black, I find more difficult to read in the dim red light used when observing, and it lacks the lamination essential to fending off destruction by dew.
Equally essential as a by­-the-telescope companion is the just-published Hartung's Astronomical Objects for Southern Telescopes, a guide to the outstanding features of the universe.
In 1968, E. J. Hartung published his Astronomical Objects for Southern Observers, which listed and described 1017 notable objects—double stars, asterisms, planetary nebulae, open and globular clusters, bright and dark nebulae and more. Now David Malin, the father of modern astrophotography, and David Frew, a science teacher and longtime amateur observer, have produced a revised, enlarged and updated edition of Hartung's work-247 pages of telescopist's delight.
The listing of objects has been increased to 1129, but as far as possible Hartung's original comments have been retained, being augmented where necessary in the light of contemporary knowledge. The original black-and-white photographs have been replaced with new ones captured especially for this edition and placed within the relevant text. There is also a selection of 64 superb colour photographs, mostly taken by the telescopes at the Anglo-Australian Telescope and showing what really is out there, if only we could get close enough for our inefficient eyes to register the colours!
The book is published by Cambridge University Press and priced at about $100, which is less than the cost of a good telescope eyepiece. Unfortunately, it is so far available only from Australia and possibly from offshore Internet bookstores such as Amazon. This revised Hartung will be the southern telescope user's friend and guide well beyond the millennium.
Peruse, use and enjoy.

Like a runway to the future, Auckland's northern motorway slices across oxidation ponds to reach Albany—a long-neglected rural backwater which is being abruptly transformed into a new city. Despite the speed of change, the district has refused to let its identity be quashed by the encroaching metropolis, and Albany in 1998 presents itself as a colourful mixture of country tenacity and urban flamboyance.

ICE. At one extreme, it is the humble cube which puts the clink in your drink on a hot summer's afternoon. At the other, it is a major cog in the engine which drives the world's weather. Further­more, its behaviour over the ages may have played a pivotal role in human evolution.
At the heart of ice's significance to the planet is that it floats on water. The arrange­ment of hydrogen and oxygen molecules in ice is more spacious than it is in liquid water, hence ice is less dense and will float on water. In most other substances the solid form is denser than the liquid form and sinks through it.
That water expands when it freezes has a number of important consequences for life on Earth. Ponds, lakes, and oceans freeze from top down, rather than from the bottom up, allowing life forms such as fish, insects and algae to survive in the liquid water beneath the ice.
The phenomenon also has ramifications for erosion. Rainwater seeping into cracks in rocks, then expand­ing when it freezes, splits the rock, actively promoting erosion. This process plays an important role in revitalis­ing the soil by adding minerals to it that are necessary for plant growth.
When it comes to changing the landscape, however, not much can compete with an advancing glacier as it sweeps soil away and grinds stones to dust. At the moment, most glaciers around the world are in retreat, but in the South Island the Franz Josef and Fox glaciers are still advanc­ing, helped by cooler El Nino weather.
There are several reasons why El Ninio contributes to the glaciers' advance. Most important is the fact that in El Nino years more snow tends to fall on top of the mountains where the glaciers start. Normally, most of the rain that falls on the West Coast of the South Island falls when temperatures are above average because it is brought by north-west winds. In summer, in particular, some of the north-west airstreams are warm enough so that even on top of the Alps it rains rather than snows.
But during El Nifio, with its predominant south-west winds, these warm rains are rare, and most, if not all, of the precipitation on top of the Southern Alps falls as snow.
Franz Josef Glacier has a very large area of snow feeding into a very narrow, steep valley. Consequently, it is very sensitive to small climate changes, and has a relatively fast response of about five years between increased snow at the top of the glacier and advance of ice at the terminus.
Another contributing factor in glacier advance is that melting at low altitudes may be significantly reduced during an El Nino. One of the best ways to melt a glacier is to surround it with warm air at near 100 per cent humidity, which is precisely what happens during normal summertime north-west rains. At such times some of the water vapour in the air condenses on to the glacial ice, but as it does so it releases heat, which melts some of the ice. Less warm rain means less melting.
Glaciers are complex entities, and are subject to other influences as well. In fine weather, the rocks of the valley walls heat up and then radiate heat on to the ice, again causing some melting. During an El Nino the predominant south-west winds produce more cloudy skies than normal during summer, west of the Alps.
The glaciers on the eastern side of the Alps, however, are retreating, and there are several reasons for this. First, these glaciers are still adjusting to a major warming trend which has been in force since the end of the last century. The adjustment is continuing because the eastern glaciers, such as the Tasman, are much slower-moving than the Franz Josef and Fox, since they travel down flatter valleys, and they have thick layers of stones and gravel on top of them, which act as insulation. Second, small lakes have formed at the snouts of these glaciers, causing much faster melting of the ice than would occur if the glacier terminated on shingle or bare rock.
For most of this century, the eastern glaciers have retreated up their valleys, leaving behind walls of shattered rock and shingle called moraines at their point of maximum advance. The moraines dam meltwater, creating the lakes. Franz Josef and Fox glaciers do not have moraine dams because their valleys are too steep, and the shingle they produce is washed straight away downstream.
The latest advance of Franz Josef Glacier is still a long way short of its position last century when it was several kilometres further down the valley. But that advance pales in comparison with its position in the last Ice Age, when it calved icebergs into the sea, which itself was more than 100 metres below today's level, and 10 km west of the present coastline.
The fact that icebergs can form only on land was known to Captain Cook, so when he encountered icebergs floating far to the south of Africa in the summer of 1772/73 he was able to deduce the existence of the Antarctic landmass even further to the south.
Ever resourceful, Cook also used some of the smaller pieces of floating ice as a source of drinking water. Taken up in baskets, the ice was let stand on the deck until the salt water had drained off, and was then was melted down and stored in barrels.
One of the few icebergs to reach New Zealand waters during European times received similar treatment when it grounded in shallow water at the Chatham Islands in October 1892. A local resident despatched a rowboat to fetch some of the ice, which was then used to make a pot of tea.
Parochial anecdotes like this have value in tracing past climatic conditions, particu­larly in areas where instru­ment readings are sparse. But well documented encounters with teapots are not the only signs that icebergs have been in the neighbourhood. For one thing, icebergs carry small rock fragments embedded in them that were torn from their glacial beds as they slid over the land. As the bergs melt, they drop these tiny stones in trails across the sea-floor.
Cores of sea-floor sediments reveal periods in the past when these stones were plentiful, indicating episodes of iceberg shedding from the continental icesheets. Measurements taken from the North Atlantic seabed and pub­lished in 1997 in the journal Science indicate a cycle of cold climate shifts about every 1500 years. One of these cycles coincides with the prolonged cold spell that occurred during medieval times and was known as the Little Ice Age.
The 1500-year cycle has also been found in measure­ments of soluble impurities in ice cores from Greenland.
Ice cores can tell us about more than just weather. Changes of acidity in the annual ice rings have been used to track down ancient volcanic eruptions. The rings confirm, for instance, that there was a large eruption at the time of Julius Caesar's death in 44 B.C., when, according to Pliny, the sky over Rome was partially obscured for nearly a year.
Shakespeare makes reference to the same cataclysm when he has Casca say to Cicero on the eve of Caesar's assassination: never till tonight, never till now, Did I go through a tempest dropping fire. Either there is a civil strife in heaven, Or else the world, too saucy with the gods, Incenses them to send destruction."
Though it melts away to nothing, ice can be enor­mously strong. Snow bridges allow people and machines to cross crevasses. Aircraft land on ice runways in Antarctica. Once, in the Napoleonic wars, a squadron of English cavalry captured a warship locked in ice.
Last summer, in Antarc­tica, a drill rig was erected on sea ice floating on the Ross Sea by a six-nation team including New Zealanders from Victoria University.
Although the project had to be cut short when the ice threatened to break up, some interesting finds were made. At a depth corresponding to 1.5 million years ago, the drill went through a metre-thick layer of sea shells, implying that the Antarctic Icesheet was much reduced at that time and tempera­tures much warmer than today.
Such warm intervals during the 2.5 million years of the Ice Ages may have been crucial to human evolution, as fossil evidence indicates that our brain size increased fourfold during this period.
The boom times that follow each retreat of the ice, when plant life and animals become more abundant in temperate latitudes such as Europe, could have pro­pelled human evolution in several ways. First, the abundance of food would have allowed a greater variety of human races to survive. In times of plenty, survival of the fittest is replaced temporarily by the survival of most.
Boom times would also favour the breeding success of those individuals who reach sexual maturity earlier. Within a few generations, their descendants would outnumber those of late maturers. More than that, there is evidence that times of abundance actually induce early sexual maturity in many species. For example, during the 1982-83 El Nino, persistent rains in the Galapagos Islands caused trees to go through seven seeding cycles in one season. The finches that feed on these seeds began breeding at the age of three months instead of the normal two years.
Similarly, the ever-decreasing age of sexual maturity in girls in many Western societies has been attributed to plentiful food supplies.Early onset of sexual maturity also goes some way to explaining the changes that have occurred in human body shape over the period of the Ice Ages. These include larger head-to-body ratio, flatter faces and smaller teeth, all of which are characteristics of juveniles in many species.
When an animal reaches sexual maturity, body development slows down dramatically. If, due to environmental factors such as abundant food supply, that stage occurs in a young animal, its juvenile features are retained into adulthood.
It may very well be that the comings and goings of the ice have made us what we are today! However, if all this seems a bit much to take in as you rattle the ice cubes in the bottom of your glass, perhaps it's time for another drink.

According to my dictionary, "fiord" (also "fjord") is a Norwegian word meaning a long, deep, narrow inlet of the sea with steep, often mountainous sides, originally eroded by glaciers.
By this definition, Fiordland is aptly named: it was glacier formed; its long inlets run to the sea and are certainly precipitous. Why is it, then, that "fiord" appears on a map of the area only in the names of the arms of Lake Te Anau?
Our true fiords are called sounds, which the dictionary defines as an inlet of the sea or a narrow channel of water, such as a strait. The South Island's other sounds, those of Marlborough, are valleys that have become drowned as the block of land on which they sit has tilted and lowered them into the Cook Strait. They are more accurately labelled sounds than the fiords of the south. Anomaly number one.
Anomaly number two is that there is absolutely no consistency in the naming of the Fiordland sounds. Not all of them are even called sounds: some are "inlets," while a number of side branches are "arms." All very confusing.
An old jingle, supposedly an aid to memorising the sounds in order from south to north, runs: Preserve your Chalk, it's Dusky at Breaksea And Dagg says it's Doubtful if Thompson went round. But Nancy and Charles go to Caswell for marble And George and Bligh to grand Milford Sound.
The trouble with this rhyme is that you have to know the position of the sounds to be able to memo­rise the verse, rather than the other way round!
The sounds are named after a variety of people and topographical features. Preservation Inlet, also called Port Preservation, probably echoes a prayer of relief by early seamen for a safe arrival. The weather in the south-west corner of our country can be of exceptional severity, but once inside the inlet, craft are in little danger from storms, being protected from the near-constant westerlies by the islands across the mouth. The name Preservation Harbour first appears on a sketch map made by an American whaler named Eber Bunker as early as 1809, but was probably in use before that date. To­wards its head, the fiord is called Long Sound—self­explanatory.
Chalky Inlet, which almost shares the same mouth as Preservation, is named after the white island at its entrance, which no doubt reminded some early seamen of the white cliffs of Dover. It forks towards its head into Edwardson Sound and Cunaris Sound. Captain Edwardson of the 29-ton schooner Snapper visited Chalky in 1822 to investigate the setting up of a flax industry. He wasn't very successful in this enterprise, but he did establish friendly relationships with local Maori (and also introduced the pig to Southland).
Jules de Blosseville, midshipman on a scientific expedition led by Louis Duperry which visited Port Jackson in 1824, obtained details of Chalky Sound from Edwardson. Duperry intended to visit the area, so de Blosseville drew a chart based on Edwardson's information and named the two arms of Chalky Inlet Bras [Ann] Edwardson and Bras Canaris. The latter was subsequently corrupted to Cunaris, but its origin is uncertain. Perhaps it refers to Konstantinos Kanaris, a hero of the Greek war of independence from Turkey well known for his use of fireships, and whose fame was likely to have spread to the French navy. Another explanation is the number of bellbirds, or "canaries," Edwardson would have heard there (and which can still be Beard today).
Dusky Sound was named By James Cook in 1770 as he passed the entrance on the evening of March 14. He actually referred to it as Duskey Bay. A second entrance is now known as Acheron Passage, named by John Stokes after his ship when he was charting the coast in 1851, but was originally called New passage by Cook, as it was sew to him. (A chart drawn By Richard Pickersgill, third lieutenant on the Resolution, allows it as Resolution lPassage.) Wet Jacket Arm, off Acheron Passage, is another of Cook's names, the boat crew that explored it baying got thoroughly soaked for their trouble.
Acheron Passage runs into Jreaksea Sound. Cook !regarded this as part of Dusky Sound and named it North Entrance, but the island at its mouth he called Breaksea Island. Early sealers applied the name Breaksea to the whole sound. This also riivides, into Vancouver and Broughton Arms, named after the captains of the two vessels that comprised George Vancouver's 1791 expedition.
Moving north, we come ao relatively small Dagg Sound, named after Captain Dagg of the whaler Scorpion, which visited the area in January 1804. But if Dagg is minor, Doubtful Sound is major. Cook named it on his first voyage, doubtful as to whether he would be able to out once he had got in. The entrance is quite narrow and wouldn't have allowed him much room to manoeu­vre, so he chose not to enter.
Doubtful Sound is actually a maze of waterways. At the eastern end of Secretary Island it is joined by Thompson Sound and Bradshaw Sound. Beyond this point it is named Malaspina Sound (or Reach). From Malaspina run First Arm, Crooked Arm and Hall Arm, with Deep Cove being a well-known anchorage at its head. Thompson Sound was named by the Sydney sealer John Grono, who operated on the Fiordland coast in 1809 and again in 1822, after the owner of his vessel, Andrew Thompson.
Stokes made the mistake of assuming it was named after a later British Colonial Secretary, Deas Thompson, and named Deas Cove, Secretary Island and Colo­nial Head in that belief. Bradshaw Sound is named after Richard Bradshaw, the mate of the Acheron. It becomes Gaer Arm further up, the derivation of which is unknown.
Nancy Sound is another small inlet. It takes its name from one of Grono's commands, and a touch of whimsy is evident in the naming of its features. The sound is leg shaped, so where it turns at right angles to the north it becomes Foot Arm, which in turn contains Heel Cove and Toe Cove. Also marked are Leg Head and Bend Point.
Charles Sound was probably named after another Sydney sealer, Charles McLaren. It forks into Emelius Arm and Gold Arm. These are probably named after ships, but there is no certainty about this.
There are two possible derivations for the name Caswell Sound. The most interesting concerns Jim Caswell, a half-caste Maori who was one of a group of sealers wrecked near the entrance of the sound. He volunteered to seek help from the sealers at Deas Cove, in Thompson Sound, and is reported to have walked and swum the distance in 48 hours. This would have included crossing the mouth of both Charles and Nancy Sounds, an improbable feat, so if he did complete the journey, it is likely he had a boat. The more prosaic explanation is that the sound was named after a neighbour of Grono's in Australia.
A fair run up the coast from Caswell is George Sound. There is some doubt as to who George was, but he was probably George Stevens, pilot of the Acheron. The name could also come from a ship, the King George, commanded by a Captain Chase, who earned a reputa­tion for his harsh treatment of northern Maori.
Bligh Sound is named only indirectly after Captain Bligh of Bounty fame. It appears to be another of Grono's ships, the Governor Bligh, which was the actual inspiration, this being the direct recipient of the name of the captain who became governor of the Port Jackson penal colony and a neighbour of Grono's on the Hawkesbury River in New South Wales. The point is probably pedantic, as the sheltered cove at the head of the sound is named Bounty Haven, and Mutiny Peak is in the vicinity, athough these were later additions to the map, made by Stokes.
Sutherland Sound is the shortest of the Fiordland sounds and the only one with restricted access from the sea. Only very small boats can enter. A feature of fiords is that they are deeper just inside the entrance than at the entrance itself. The weight and grinding action of a glacier diminishes at its snout, which means a fiord shoals towards the mouth. This characteristic is particu­larly pronounced in Suther­land, making the sound more akin to a big lagoon with similarities to Lake McKerrow and the Hollyford Valley, which lie to the north of the sounds. It was named after Donald Sutherland, who first entered it by rowing down the coast from his home at Milford in 1883.
Finally, there is "grand" Milford Sound, one of the half-dozen or so natural features of the country familiar from calendars and postcards to most of the populace. To sail in on a fine day, however, is still to be surprised at just how grand it is. The surrounding country is higher than further south, and near Dale Point the walls of the fiord are very close together. Grono was again responsible for the name: Milford Haven, as the sound was known for a time, was a town close to Grono birth­place in south Wales.
Maori legend attributes the formation of the sounds to the god Tu Te Raki Whanoa, who began in unpractised fashion on the southern ones, which is why these are ragged and scat­tered with islands. As he progressed northwards, Tu Te Raid's workmanship steadily improved, and by the time he came to shape Milford he had perfected his technique. As with so many Maori accounts of the formation of natural features, this explanation is most apposite. Milford is one of the geographical wonders of the country.

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